Influence of stent-induced vessel deformation on hemodynamic feature of bloodstream inside ICA aneurysms

One of the effective treatment options for intracranial aneurysms is stent-assisted coiling. Though, previous works have demonstrated that stent usage would result in the deformation of the local vasculature. The effect of simple stent on the blood hemodynamics is still uncertain. In this work, hemodynamic features of the blood stream on four different ICA aneurysm with/without interventional are investigated. To estimate the relative impacts of vessel deformation, four distinctive ICA aneurysm is simulated by the one-way FSI technique. Four hemodynamic factors of aneurysm blood velocity, wall pressure and WSS are compared in the peak systolic stage to disclose the impact of defamation by the stent in two conditions. The stent usage would decrease almost all of the mentioned parameters, except for OSI. Stenting reduces neck inflow rate, while the effect of interventional was not consistent among the aneurysms. The deformation of an aneurysm has a strong influence on the hemodynamics of an aneurysm. This outcome is ignored by most of the preceding investigations, which focused on the pre-interventional state for studying the relationship between hemodynamics and stents. Present results show that the application of stent without coiling would improve most hemodynamic factors, especially when the deformation of the aneurysm is high enough.

Endoscopic clipping of an anterior communicating artery aneurysm

BACKGROUND

Anterior communicating artery aneurysms are most prone to rupture. Surgically, they are conventionally being managed by a pterional approach. Some neurosurgeons prefer a supraorbital keyhole approach in select cases. Fully endoscopic clipping of such aneurysms is seldom described.

METHOD

We clipped an antero-inferiorly directed anterior communicating artery aneurysm endoscopically via a supraorbital keyhole approach. The intraoperative aneurysmal rupture was also managed endoscopically. The patient made an excellent postoperative recovery without any neurological deficits.

CONCLUSION

Select cases of anterior communicating artery aneurysms can be clipped endoscopically using standard instruments and adhering to the basic principles of aneurysm clipping.

Acute Subdural Hematoma Associated with Aneurysmal Rupture: A Case Series and Review of Literature

BACKGROUND

Ruptured cerebral aneurysms represent a neurosurgical emergency with characteristic clinical presentation and imaging findings. However, atypical presentations may occur in association with acute subdural hematomas (SDHs).

METHODS

A retrospective review was conducted at our institution between 2013 and 2021 to identify patients with aneurysmal rupture presenting with SDH. Cases were reviewed for clinical presentation, imaging findings, management, and outcome.

RESULTS

A total of 8 patients were included in this review with an average age of 48.5 years. Six patients were women. The average Glasgow coma scale upon arrival was 6.3, and the Hunt-Hess average grade was 4.6. Aneurysm locations included posterior communicating artery (n = 3), anterior communicating artery (n = 2), middle cerebral artery (n = 2), and internal carotid artery terminus (n = 1). The size of aneurysm varied between 3 and 11 mm. Seven patients required surgical intervention, either craniotomy or craniectomy for hematoma evacuation, and aneurysms were treated by coiling (n = 2) or clipping (n = 6).

CONCLUSIONS

Ruptured aneurysms may present with SDH with or without significant subarachnoid hemorrhage. This illustrative case series highlights this challenging presentation and the importance of early recognition and appropriate management.

PulseRider-assisted coil embolization for an unruptured internal carotid artery-persistent primitive trigeminal artery aneurysm

A persistent primitive trigeminal artery (PPTA) is a vessel remnant of carotid-vertebrobasilar anastomosis. The aneurysm at the bifurcation of the internal carotid artery (ICA) and PPTA tends to have a broad neck with the branch incorporated into the sac. Because PPTA supplies to the posterior circulation and branches off direct pontine perforators, PPTA preservation should always be considered when treating PPTA aneurysms to avoid ischemic complications.We report a case of the wide-neck ICA-PPTA aneurysm successfully treated with the PulseRider-assisted coil embolization, resulting in complete occlusion with PPTA patency. Relevant anatomy and endovascular strategy of the PPTA aneurysms are discussed.

Results of Double Low-Profile Visualized Intraluminal Support Blue Stenting for the Treatment of Fusiform Cerebral Aneurysms

BACKGROUND

The flow diversion technique is increasingly used for reconstructive endovascular treatment of fusiform cerebral aneurysms. Double stenting with the Low-profile Visualized Intraluminal Support (LVIS) Blue stent is one of the flow diversion techniques. The aim of this study was to analyze the clinical and angiographic outcomes of LVIS Blue double stenting for fusiform cerebral aneurysms.

METHODS

Between March 2016 and July 2020, double LVIS Blue stenting was attempted in 25 fusiform cerebral aneurysms. Patient medical records and radiological images were carefully reviewed.

RESULTS

The technical success rate was 100% (25/25). Six aneurysms (24.0%) were located in the anterior circulation and 19 aneurysms (76.0%) were located in the posterior circulation. Intraprocedural thromboembolic complications occurred in 1 patient (4.0%). During the follow-up period (30.8 ± 14.2 months), there were no deaths or delayed complications. The mean angiographic follow-up duration was 28.2 ± 12.8 months. Follow-up angiography revealed complete obliteration (O'Kelly-Marotta D) in 21 (84.0%) patients and near-complete obliteration (O'Kelly-Marotta C + 2 matched with Kamran-Byrne grade 3) in 2 (8.0%) patients. Two patients (8.0%) showed worsening of obliteration grades. One (4.0%) patient required retreatment. There was no significant in-stent stenosis or branch occlusion covered by stents.

CONCLUSIONS

Double stenting using LVIS Blue stents for the treatment of fusiform cerebral aneurysms is effective and safe.

Influence of blood viscosity models and boundary conditions on the computation of hemodynamic parameters in cerebral aneurysms using computational fluid dynamics

BACKGROUND

Computational fluid dynamics (CFD) is widely used to calculate hemodynamic parameters that are known to influence cerebral aneurysms. However, the boundary conditions for CFD are chosen without any specific criteria. Our objective is to establish the recommendations for setting the analysis conditions for CFD analysis of the cerebral aneurysm.

METHOD

The plug and the Womersley flow were the inlet boundary conditions, and zero and pulsatile pressures were the outlet boundary conditions. In addition, the difference in the assumption of viscosity was analyzed with respect to the flow rate. The CFD process used in our research was validated using particle image velocimetry experiment data from Tupin et al.'s work to ensure the accuracy of the simulations.

RESULTS

It was confirmed that if the entrance length was sufficiently secured, the inlet and outlet boundary conditions did not affect the CFD results. In addition, it was observed that the difference in the hemodynamic parameter between Newtonian and non-Newtonian fluid decreased as the flow rate increased. Furthermore, it was confirmed that similar tendencies were evaluated when these recommendations were utilized in the patient-specific cerebral aneurysm models.

CONCLUSIONS

These results may help conduct standardized CFD analyses regardless of the research group.

Dense, deep learning-based intracranial aneurysm detection on TOF MRI using two-stage regularized U-Net

BACKGROUND AND PURPOSE

The prevalence of unruptured intracranial aneurysms in the general population is high and aneurysms are usually asymptomatic. Their diagnosis is often fortuitous on MRI and might be difficult and time consuming for the radiologist. The purpose of this study was to develop a deep learning neural network tool for automated segmentation of intracranial arteries and automated detection of intracranial aneurysms from 3D time-of-flight magnetic resonance angiography (TOF-MRA).

MATERIALS AND METHODS

3D TOF-MRA with aneurysms were retrospectively extracted. All were confirmed with angiography. The data were divided into two sets: a training set of 24 examinations and a test set of 25 examinations. Manual annotations of intracranial blood vessels and aneurysms were performed by neuroradiologists. A double convolutional neuronal network based on the U-Net architecture with regularization was used to increase performance despite a small amount of training data. The performance was evaluated for the test set. Subgroup analyses according to size and location of aneurysms were performed.

RESULTS

The average processing time was 15 min. Overall, the sensitivity and the positive predictive value of the proposed algorithm were 78% (21 of 27; 95% CI: 62-94) and 62% (21 of 34; 95%CI: 46-78) respectively, with 0.5 FP/case. Despite gradual improvement in sensitivity regarding aneurysm size, there was no significant difference of sensitivity detection between subgroups of size and location.

CONCLUSIONS

This developed tool based on a double CNN with regularization trained with small dataset, enables accurate intracranial arteries segmentation as well as effective aneurysm detection on 3D TOF MRA.

Modeling Flow in Cerebral Aneurysm After Coils Embolization Treatment: A Realistic Patient-Specific Porous Model Approach

PURPOSE

Computational fluid dynamics (CFD) has been used to evaluate the efficiency of endovascular treatment in coiled cerebral aneurysms. The explicit geometry of the coil mass cannot typically be incorporated into CFD simulations since the coil mass cannot be reconstructed from clinical images due to its small size and beam hardening artifacts. The existing methods use imprecise porous medium representations. We propose a new porous model taking into account the porosity heterogeneity of the coils deployed in the aneurysm.

METHODS

The porosity heterogeneity of the coil mass deployed inside two patients' cerebral aneurysm phantoms is first quantified based on 3D X-ray synchrotron images. These images are also used to compute the permeability and the inertial factor arising in porous models. A new homogeneous porous model (porous crowns model), considering the coil's heterogeneity, is proposed to recreate the flow within the coiled aneurysm. Finally, the validity of the model is assessed through comparisons with coil-resolved simulations.

RESULTS

The strong porosity gradient of the coil measured close to the aneurysmal wall is well captured by the porous crowns model. The permeability and the inertial factor values involved in this model are closed to the ideal homogeneous porous model leading to a mean velocity in the aneurysmal sac similar as in the coil-resolved model.

CONCLUSION

The porous crowns model allows for an accurate description of the mean flow within the coiled cerebral aneurysm.

Reversible and multiphasic parenchymal changes in MRI after coil embolization for a ruptured cerebral aneurysm

Background

Reversible and multiphasic parenchymal changes in magnetic resonance imaging (MRI) are exceedingly rare. The authors experienced a case of reversible and multiphasic parenchymal changes in MRI after coil embolization for a ruptured cerebral aneurysm.

Case Description

A 48-year-old woman had a sudden onset of severe headaches and was referred to us for coil embolization. She was alert-oriented and had no neurologic deficits. Her medical history was atopic dermatitis and metal allergy. A head computed tomography (CT) scan demonstrated subarachnoid hemorrhage, and three-dimensional-CT angiography revealed a left internal carotid artery-posterior communicating artery aneurysm. Coil embolization was performed on the next day and seven coils made by three different manufacturers were used for the embolization. Despite no neurologic deficits after the surgery and no abnormal findings in MRI 7 days after the coil embolization, an MRI 2 weeks after embolization demonstrated delayed multiple white matter high intense lesions on T2-weighted image and fluid-attenuated inversion recovery in the left hemisphere. Repeat MRI scans showed multiple high intense lesions at various locations and at different timings. The blood test revealed the elevation of the proportion of EOS up to 9.7%, strongly indicating some allergic response. The MRI scan obtained 3 months after the onset confirmed the complete disappearance of the lesions.

Conclusion

Given her history of metal allergy, and the reversible and multiphasic lesions in the non-vascular territories of the treated aneurysm, metal allergic encephalitis was most likely despite no clear evidence.

Duplicated fetal posterior cerebral artery in a patient with a ruptured fetal posterior cerebral artery aneurysm: a cerebrovascular variant

BACKGROUND

The most common neurovascular variant is the fetal posterior cerebral artery (FPCA), in which the P1 branch is absent or hypoplastic, and the majority of P2 supply is derived from the anterior circulation. While there are reports of hyperplastic anterior choroidal arteries (AChA) with supply to the temporo-occipital and calcarine regions, no reports of a duplicated FPCA exist.

METHODS

This case report describes a patient with a ruptured right FPCA aneurysm. Digital subtraction angiogram (DSA) revealed an artery with origin distal to the FPCA associated with the aneurysm. This was not consistent with a typical AChA. The FPCA associated with the aneurysm had the typical origin, course, and supply of a FPCA. The distal FPCA had a similar course of a typical FPCA with significant supply to the typical PCA territory. The patient underwent successful clipping of the aneurysm, and the duplicated FPCA was identified during the craniotomy.

RESULTS

The features of this duplicate FPCA, which has not been previously described, are discussed in comparison to another variant, the hyperplastic, anomalous AChA. The artery described in this report does not fit the typical criteria of this AChA variant. Therefore, the authors outline this variant as a duplicated FPCA.

CONCLUSION

Recognition of variant cerebrovascular anatomy is vital to neurosurgeons and interventional neuroradiology specialists. FPCA aneurysms require special management considerations and are often more challenging to treat. This report discusses a duplicated FPCA. To our knowledge, this is the first description of this variant. A duplicated FPCA carries important management considerations in the management of neurovascular pathology.

High-fidelity fluid structure interaction simulations of turbulent-like aneurysm flows reveals high-frequency narrowband wall vibrations: A stimulus of mechanobiological relevance?

Recent high-fidelity/resolution computational fluid dynamics simulations of intracranial aneurysm hemodynamics have revealed turbulent-like flows. We hypothesized that the associated high-frequency pressure fluctuations could promote aneurysm wall vibrations. We performed fully coupled high-fidelity transient fluid structure interaction simulations between the blood flow and compliant aneurysm sac wall taking 5,000 time steps per second using a 3D patient-specific model previously shown to harbour turbulent-like flow. Our results show that the flow velocity contained fluctuations with a smooth and continuously decaying energy up to ∼160Hz, and fluctuating pressures with characteristic frequency peaks at approximately 30, 130 and 210Hz. There was a strong two-way coupling between the pressure and the wall deformation, for which the frequency spectrum showed similar characteristics, but with a narrow band peak at ∼120Hz with large regional differences in amplitude up to 80μm. The physics of the flow is broadly consistent with clinical reports of turbulent-like flows, while the physics of the wall is consistent with reports of spectral peaks in aneurysm patients. As many aneurysms are known to harbour turbulent-like flows, wall vibrations could be a widespread phenomenon. Finally, since aneurysms are vascular pathologies by definition and many/most aneurysms do not have endothelial cells but still display a focal remodeling, we hypothesize that vibrations and stresses within the wall itself might play a role in the mechanobiological processes of vessel wall pathology.

Long-term efficacy and safety of WovenEndoBridge (WEB)-assisted cerebral aneurysm embolization

PURPOSE

Long-term compaction, compression, migration, and recurrence rates of the WovenEndoBridge devices remain unknown. The purpose of this study was to detect these rates and safety profiles of the WovenEndoBridge within 7 years period.

MATERIALS AND METHODS

Eighty-three aneurysms of 79 patients treated with the WovenEndoBridge device were retrospectively evaluated using an occlusion scale (e.g. complete occlusion, neck remnant, and aneurysm remnant) on angiography images.

RESULTS

The residual aneurysm was observed in 11 (13%) aneurysms. The mean and median diameters of the recurrent aneurysms were 6 and 7 mm. Most of the recurrent aneurysms were complex type and/or ruptured. Mean diameters and the neck-to-body ratios of all residual aneurysms in the preoperative imaging exams were above 4 mm and 0.6, respectively. The median values of preoperative height and neck measurements were higher in the recurrent aneurysms than in the adequate occlusion group (p = 0.006, p = 0.019, respectively). There was a statistically significant positive relationship between preoperative height/neck measurements and the mean diameters of residual aneurysms (rs = 0.32 and p = 0.003; rs = 0.28 and p = 0.011, respectively). The WovenEndoBridge compaction/compression and migration were observed in 5 (45%) and 2 (18%) of the recurrent aneurysms. In 7 (64%) of the residual aneurysms, thrombosed areas were found within the aneurysm. In the follow-up period, four aneurysms (4.8%) were retreated due to widened residual aneurysm. Other aneurysms were improved or stable within 7 years.

DISCUSSION

Our adequate occlusion rate was 87%. Occlusion rates are less favorable than aneurysms with a long height, wide neck, or high neck-to-body ratio. Our study confirms the high safety and efficiency of the WovenEndoBridge. Compaction, compression, and/or migration of the WovenEndoBridge and the presence of intra-aneurysmal thrombosis are the main reasons for the recurrences.

Ruptured cerebral aneurysm in isolated type A interrupted aortic arch managed by transradial endovascular route: A case report with literature review

BACKGROUND AND INTRODUCTION

Interrupted aortic arch (IAA) is a very rare congenital anomaly carrying high neonatal mortality rate if left untreated. Rarer still, is its presentation in teenage or adulthood. This condition has been found to be complicated with cerebral aneurysms, which is a consequence of hemodynamic stress and hypertension secondary to arch interruption. Cerebral aneurysms can further complicate the clinical course and lead to poor clinical outcomes, especially if ruptured.

CLINICAL PRESENTATION

A 17-year-old female presented with ruptured basilar top aneurysm and was considered for endovascular coiling. Transfemoral access was chosen but the catheter could not be negotiated beyond proximal thoracic aorta. A computed tomographic angiography (CTA) of thorax and abdomen was performed, which showed isolated interruption of aortic arch. Subsequently, transradial route was used for coiling of the aneurysm.

CONCLUSION

To the best of our knowledge, the index case is one of the only seven cases of IAA with cerebral aneurysm that have been reported till date in medical literature. It also holds the unique distinction of being the first case of IAA with cerebral aneurysm treated by endovascular approach. Our case highlights the importance of transradial access in such pathological conditions.

Treatment results of anterior choroidal artery aneurysms treated mostly with coil embolization: A single-center experience

BACKGROUND

Anterior choroidal artery (AchA) aneurysms are usually small in diameter because of the size of the involved artery and are often wide-necked. Coil embolization of AchA aneurysm is thus challenging because of serious risks, such as thromboembolic occlusion of artery and perforation of aneurysm dome. Therefore, aneurysmal neck clipping remains widely performed despite a recent increase in the use of coil embolization for aneurysm treatment. We report the treatment results of AchA aneurysms mostly (92.3%) treated with coil embolization at our institute.

METHODS

The database and medical records of patients who underwent coil embolization for AchA aneurysms were retrospectively analyzed. The clinical and imaging results and procedure-related complications were investigated after coil embolization performed between January 2006 and March 2022 at our institute.

RESULTS

In total, 96 AchA aneurysms comprising 65 unruptured and 31 ruptured aneurysms, including only 1 ruptured aneurysm (1.0%) re-embolized at postoperative day 192 because of coil compaction, were evaluated. After the initial coil embolization, complete occlusion was attained in 41, residual neck in 45, and residual aneurysm in 10 patients. Follow-up radiological studies after 6-174 months were performed for 80 aneurysms. Complete occlusion was noted in 57 patients, residual neck in 22, and residual aneurysm in 1. The dysarthria experienced by one (1.0%) patient was the only symptomatic procedure-related complication. After coil embolization, neither delayed new rupture nor re-rupture was observed.

CONCLUSIONS

The results of this study demonstrate that coil embolization is a safe and effective treatment option for patients with AchA aneurysms.

Wire perforation of the missed tiny aneurysm originating from the fenestrated A1 segment during the endovascular approach

Vascular anomaly and aneurysmal formation of an anterior communicating artery (ACOM) complex has often been reported. Because of such a complicated relationship between the vascular structure and aneurysms, ACOM aneurysm is one of the most difficult aneurysms to treat among other common anterior circulation aneurysms. We herein report a case of wire perforation of a missed tiny aneurysm arising from the fenestrated A1 segment during the endovascular approach to ACOM aneurysm. Although the fenestration of A1 segment is a rare vascular anomaly, it is likely to accompany saccular type aneurysms in the vicinity of the vascular anomaly. Endovascular treatment for ACOM aneurysm requires more detailed evaluations of the accompanying vascular anomaly and hemodynamics around ACOM to avoid complications.

Wall Shear Stress Estimation for 4D Flow MRI Using Navier-Stokes Equation Correction

This study introduces a novel wall shear stress (WSS) estimation method for 4D flow MRI. The method improves the WSS accuracy by using the reconstructed pressure gradient and the flow-physics constraints to correct velocity gradient estimation. The method was tested on synthetic 4D flow data of analytical Womersley flow and flow in cerebral aneurysms and applied to in vivo 4D flow data acquired in cerebral aneurysms and aortas. The proposed method's performance was compared to the state-of-the-art method based on smooth-spline fitting of velocity profile and the WSS calculated from uncorrected velocity gradient. The proposed method improved the WSS accuracy by as much as 100% for the Womersley flow and reduced the underestimation of mean WSS by 39 to 50% for the synthetic aneurysmal flow. The predicted mean WSS from the in vivo aneurysmal data using the proposed method was 31 to 50% higher than the other methods. The predicted aortic WSS using the proposed method was 3 to 6 times higher than the other methods and was consistent with previous CFD studies and the results from recently developed methods that take into account the limited spatial resolution of 4D flow MRI. The proposed method improves the accuracy of WSS estimation from 4D flow MRI, which can help predict blood vessel remodeling and progression of cardiovascular diseases.

An Unusual Etiology: Subarachnoid Hemorrhage Resulting in Transient Apical Ballooning Syndrome

Intracranial bleeds, such as subarachnoid hemorrhage, carry high morbidity and mortality rates. Often intracranial hemorrhages result in debilitating residual neurological symptoms but can be so extensive that cardiac complications can also be seen. We present a rare case of a patient who was found to have a subarachnoid hemorrhage that incited the development of Takotsubo cardiomyopathy, which subsequently progressed to an acute myocardial infarction. The aim of this case report is to explore the underlying pathophysiology of how cerebral hemorrhage can result in apical ballooning of the left ventricle through various mechanisms including sympathetic-induced surge in catecholamines and neurogenic damage to the myocardium. We also intend to highlight the importance for clinicians to consider brain bleeds in the differential diagnosis when a patient presents with an acute myocardial infarction as treatment with heparin is generally contraindicated.

A Rare and Unusual Cause of Ischemic Stroke to Be Aware of

Congenital absence of an internal carotid artery (ICA) is an extremely rare vascular anomaly. This case report presents an instance of right ICA agenesis to highlight the importance of early identification of this anomaly and its impact on disease presentation and complications. With transient ischemic attack (TIA), cerebrovascular accident (CVA), and cerebral aneurysms being among the chief presenting scenarios or course of the anomaly, it is important to have a high level of suspicion for these in patients with known ICA agenesis. Understanding the underlying development of this vasculature and its impact on cerebral circulation aids in identifying possible findings on imaging. This case report aims to delineate the pathophysiology of ICA agenesis, recognition of the vasculature that contributes to the anomaly, different presentations of the disease, complications, and obstacles in management.

A coarse-to-fine cascade deep learning neural network for segmenting cerebral aneurysms in time-of-flight magnetic resonance angiography

BACKGROUND

Accurate segmentation of unruptured cerebral aneurysms (UCAs) is essential to treatment planning and rupture risk assessment. Currently, three-dimensional time-of-flight magnetic resonance angiography (3D TOF-MRA) has been the most commonly used method for screening aneurysms due to its noninvasiveness. The methods based on deep learning technologies can assist radiologists in achieving accurate and reliable analysis of the size and shape of aneurysms, which may be helpful in rupture risk prediction models. However, the existing methods did not accomplish accurate segmentation of cerebral aneurysms in 3D TOF-MRA.

METHODS

This paper proposed a CCDU-Net for segmenting UCAs of 3D TOF-MRA images. The CCDU-Net was a cascade of a convolutional neural network for coarse segmentation and the proposed DU-Net for fine segmentation. Especially, the dual-channel inputs of DU-Net were composed of the vessel image and its contour image which can augment the vascular morphological information. Furthermore, a newly designed weighted loss function was used in the training process of DU-Net to promote the segmentation performance.

RESULTS

A total of 270 patients with UCAs were enrolled in this study. The images were divided into the training (N = 174), validation (N = 43), and testing (N = 53) cohorts. The CCDU-Net achieved a dice similarity coefficient (DSC) of 0.616 ± 0.167, Hausdorff distance (HD) of 5.686 ± 7.020 mm, and volumetric similarity (VS) of 0.752 ± 0.226 in the testing cohort. Compared with the existing best method, the DSC and VS increased by 18% and 5%, respectively, while the HD decreased by one-tenth.

CONCLUSIONS

We proposed a CCDU-Net for segmenting UCAs in 3D TOF-MRA, and the obtained results show that the proposed method outperformed other existing methods.

Diffusion-weighted imaging-positive lesions following endovascular treatment for ruptured and unruptured aneurysms: Its incidence according to antithrombotic drugs

Objective

Microembolic infarcts are frequently observed on diffusion-weighted imaging (DWI) following endovascular treatment. We investigated DWI-positive lesions and symptomatic ischemic complications (SICs) in patients with ruptured and unruptured aneurysms following coiling and the relationship between DWI-positive lesions and antithrombotic drugs.

Methods

Between January 2016 and December 2020, 83 patients underwent DWI within 48 h following endovascular treatment for ruptured (n=30) and unruptured (n=53) aneurysms.

Results

The overall rate of DWI-positive lesions was 55.4%. There were no significant differences in the occurrence rate (45.3% vs. 43.3%, p=1.000) and the number of lesions (2.7±4.6 vs. 4.0±5.3, p=0.237) between unruptured and ruptured aneurysms. SIC occurred more frequently in patients with ruptured aneurysms than unruptured ones (20.0% vs. 1.9%, p=0.015). The cutoff value of DWI-positive lesions for predicting SIC was 5 (sensitivity 100%, specificity 78.9%). The procedure time was significantly longer in patients with DWI-positive lesions ≥5 than those with DWI-positive lesions <5 (104.1±43.8 vs. 85.1±30.8 min, p=0.030). Patients with DWI-positive lesions <5 were more frequently observed in the postprocedural heparinization group than in the no heparinization group (85.7% vs. 58.5%, p=0.012).

Conclusions

The incidence of DWI-positive lesions did not differ significantly between the ruptured and unruptured aneurysms. However, SIC occurred more frequently in patients with ruptured aneurysms. Longer procedure time is a risk factor for DWI-positive lesions, and postprocedural heparinization seems to reduce the incidence of DWI-positive lesions.

Single Center Retrospective Analysis of Cerebral Aneurysms from a Patient Sample Data Collection at a Comprehensive Stroke Center

INTRODUCTION

Institutional self-monitoring of cerebral aneurysm data should occur regularly. The objective of this retrospective single center study was to examine the reproducibility of a data collection and analytic method to examine cerebral aneurysm characteristics and trends.

METHODS

A single center retrospective analysis was performed from 2018 to 2021 of the most recent 100 patient presentations with a newly diagnosed cerebral aneurysm. Data collection included patient demographics, radiographic features, ruptured or unruptured status, location, grading scale, treatment strategy, survival, and length of stay, which were extracted and presented in tabular form and analyzed for overall trends.

RESULTS

Of the collected 100 patients meeting ICD-10 criteria, 10 (10%) patients were excluded due to having been previously diagnosed at the institution and not meeting the criteria of a new discovery of cerebral aneurysm for inclusion. The remaining 90 sample patients presented with newly diagnosed aneurysms to the authors' Emergency Department between 2018 and 2021. Most patients were between the ages of 25 and 65 with 55 (61%) patients identifying themselves as female sex. Of the 90 eligible sample patients, 59 (66%) had aneurysms that were not ruptured. Eighty-eight (97.7%) patients had cerebral aneurysms that were < 7mm in size. The most common location for aneurysms was in the anterior cerebral circulation, with identification of 27 middle cerebral artery aneurysms. Length of stay (LOS) ranged from 0-171 days with a mean of 11.97 days (SD = 19.9). Of the seven (7.7%) patients who expired, four (57%) experienced spontaneous subarachnoid hemorrhages, with two (29%) occurring in the anterior communicating artery and one (14%) in the left middle cerebral artery and basilar artery respectively.

CONCLUSIONS

The typical presentation of a cerebral aneurysm is unruptured with a pre-dominance in middle-aged females. Our findings are congruent with the literature regarding the location of the aneurysm originating in the anterior circulation. However, most aneurysms in our clinical cohort were located on the MCA/ICA in contrast to the literature reported (i.e., most anterior communicating artery). Of those patients who presented unruptured, outpatient follow-up and routine monitoring were appropriate with medical management in the setting of small aneurysms. The risk of progression and subsequent rupture was relatively small in this patient cohort. Multi-year examinations of single institution comprehensive stroke centers regarding cerebral aneurysms would enable researchers to conduct regional analyses and comparisons to national and international trends.

Lymphatic vessels are present in human saccular intracranial aneurysms

Saccular intracranial aneurysm (sIA) rupture leads to subarachnoid haemorrhage and is preceded by chronic inflammation and atherosclerotic changes of the sIA wall. Increased lymphangiogenesis has been detected in atherosclerotic extracranial arteries and in abdominal aortic aneurysms, but the presence of lymphatic vessels in sIAs has remained unexplored. Here we studied the presence of lymphatic vessels in 36 intraoperatively resected sIAs (16 unruptured and 20 ruptured), using immunohistochemical and immunofluorescence stainings for lymphatic endothelial cell (LEC) markers. Of these LEC-markers, both extracellular and intracellular LYVE-1-, podoplanin-, VEGFR-3-, and Prox1-positive stainings were detected in 83%, 94%, 100%, and 72% of the 36 sIA walls, respectively. Lymphatic vessels were identified as ring-shaped structures positive for one or more of the LEC markers. Of the sIAs, 78% contained lymphatic vessels positive for at least one LEC marker. The presence of LECs and lymphatic vessels were associated with the number of CD68+ and CD163+  cells in the sIA walls, and with the expression of inflammation indicators such as serum amyloid A, myeloperoxidase, and cyclo-oxygenase 2, with the presence of a thrombus, and with the sIA wall rupture. Large areas of VEGFR-3 and α-smooth muscle actin (αSMA) double-positive cells were detected in medial parts of the sIA walls. Also, a few podoplanin and αSMA double-positive cells were discovered. In addition, LYVE-1 and CD68 double-positive cells were detected in the sIA walls and in the thrombus revealing that certain CD68+ macrophages are capable of expressing LEC markers. This study demonstrates for the first time the presence of lymphatic vessels in human sIA walls. Further studies are needed to understand the role of lymphatic vessels in the pathogenesis of sIA.

Cumulative Radiation Exposure in Aneurysmal Subarachnoid Hemorrhage: A Single-Institution Analysis

OBJECTIVE

Diagnosis and management of aneurysmal subarachnoid hemorrhage (aSAH) depend heavily on imaging modalities that repeatedly expose patients to ionizing radiation. There is limited literature on cumulative radiation exposure in this patient population, which is a problem compounded by wide variation among institutions. The present study quantifies the cumulative cranial exposure to ionizing radiation resulting from diagnostic medical imaging and medical procedures during initial hospitalization for ruptured aSAH at a single academic institution and estimates the risk of future adverse events related to radiation injury.

METHODS

We performed a retrospective observational study of adults who presented to our institution during a nearly 3-year period with acute-onset aSAH, which was confirmed with diagnostic imaging, and had the aneurysm treated with either surgical clip ligation or endovascular embolization.

RESULTS

A total of 131 patients met the inclusion criteria. Eighty-eight patients (67%) were treated with endovascular embolization and 43 (32%) were treated with clip ligation. We found the average radiation dose to the head during the incident hospitalization for aSAH to be 4.40 Gy (95% confidence interval, 3.91-4.89). Angiography and interventional radiology procedures accounted for most of this exposure.

CONCLUSIONS

Most patients were exposed to levels of ionizing radiation that put them at considerable risk of deterministic radiation injury. Providers should be aware of the potential consequences of acute and long-term radiation exposure in this patient population, so they can monitor and counsel individuals accordingly and take steps to safely limit radiation exposure during aSAH management.

Feasibility and Safety of Transradial Aneurysm Embolization: A Systematic Review and Meta-Analysis

OBJECTIVE

Use of the transradial access (TRA) approach for neuroendovascular procedures has been increasing in recent years. Our aim is to assess the feasibility, success rate, and complications associated with TRA for intracranial aneurysm embolization.

METHODS

PubMed, Scopus, and Embase were systematically searched for studies using TRA for intracranial aneurysm embolization. Random-effects models were used to obtain pooled rates of procedural success and complications.

RESULTS

Twenty-four studies comprising 1283 (85.9%) TRA and 122 (8.2%) distal TRA aneurysm embolization procedures were included. The pooled success rate of the 18 studies in the meta-analysis was 93.5% (95% confidence interval [CI], 91.1%-95.8%). The pooled thromboembolic complication rate was 0.5% (95% CI, 0.1%-0.9%), the hemorrhagic complication rate was 0.5% (95% CI, 0.1%-0.9%), and the access site complication rate was 0.8% (95% CI, 0.3%-1.3%). One study (4.3%) used exclusively a 7-French guide catheter, and most used a 6-French guide catheter (22 of 23 studies, 95.7%), which was further incorporated as part of a triaxial configuration through a sheathless 8-French system in 4 studies (17.4%), 7-French guide catheter in 2 studies (8.7%), and 8-French sheath in 1 study (4.3%). The embolization techniques used were flow diverter placement in 451 cases (39.1%), coiling in 376 (32.6%), stent-assisted coiling in 127 (11.0%), balloon-assisted coiling in 104 (9.0%), Woven EndoBridge system in 50 (4.3%), and flow diverter placement plus coiling in 42 (3.6%).

CONCLUSIONS

Treating intracranial aneurysms using various embolization techniques through TRA is feasible and associated with low access site and intraoperative complications.

Alien hand syndrome in ruptured aneurysms: case report and review of the literature

Alien hand syndrome is a rare condition associated with lesions of the corpus callosum and of the supplementary motor area, which can be caused by ruptured cerebral aneurysms. We present a novel case of a patient with a subarachnoid haemorrhage from an aneurysm of the anterior communicating artery who developed alien hand syndrome and intermanual conflict. In addition, we performed a systematic literature search and evaluated data on clinical presentation, treatment and radiological findings from relevant papers. To date, 17 cases of alien hand syndrome in aneurysmatic subarachnoid haemorrhage have been reported. Aneurysms of the anterior communicating artery were the most common origin of subarachnoid haemorrhage (10/17), followed by pericallosal artery aneurysms (7/10). The prognosis appears to be favourable; however, damage to the supplementary motor area during treatment should be avoided to keep symptoms minimal.

Stent-assisted coiling of acutely ruptured cerebral aneurysm: a multicenter prospective registry study (SAVE)

Background

Stent-assisted coiling (SAC) has been reported as a feasible and effective treatment of wide-neck cerebral aneurysms. However, the evidence of SAC of ruptured cerebral aneurysm is lacking. There are no prospective multicenter studies regarding SAC of acutely ruptured aneurysms within 72 hours after subarachnoid hemorrhage. The purpose of the study is to evaluate the safety and efficiency of SAC of acutely ruptured cerebral aneurysms.

Methods

This study is a prospective, multicenter, and observation registry of consecutive patients with acutely ruptured cerebral aneurysms treated with SAC. Acutely ruptured aneurysms were confirmed within 72 h after the onset of the syndrome. This study will enroll at least 300 patients in 7 high-volume tertiary hospitals (more than 150 cerebral aneurysms treated per year). The primary outcomes are treatment-related thromboembolic complications within 30 days of the treatment. The secondary outcomes are any hemorrhagic complications and aneurysm recurrence at 6 months of angiographic follow-up. The clinical outcomes are measured with the Modified Rankin Scale (mRS) at discharge and at the 6 months of follow-up. The favorable outcomes are defined as an mRS of grades 0 and 2.

Discussion

We will perform a prospective, multicenter, and observational registry study of consecutive patients with wide-neck acutely ruptured cerebral aneurysms to improve the safety strategy of SAC of acutely ruptured cerebral aneurysms.

Trial registration

Chinese Clinic Trial Registry: ChiCTR2000036972; Registration date: Aug 26, 2020

An imbalance between RAGE/MR/HMGB1 and ATP1α3 is associated with inflammatory changes in rat brain harboring cerebral aneurysms prone to rupture

BACKGROUND AND PURPOSE

An aneurysmal subarachnoid hemorrhage is a devastating event. To establish an effective therapeutic strategy, its pathogenesis must be clarified, particularly the pathophysiology of brain harboring intracranial aneurysms (IAs). To elucidate the pathology in brain harboring IAs, we examined the significance of the receptor for advanced glycation end-products (RAGE)/mineralocorticoid receptor (MR) pathway and Na⁺/K⁺-ATPase (ATP1α3).

METHODS

Ten-week-old female rats were subjected to oophorectomy as well as hypertension and hemodynamic changes to induce IAs, and were fed a high-salt diet. Brain damage in these rats was assessed by inflammatory changes in comparison to sham-operated rats fed a standard diet.

RESULTS

Six weeks after IA induction (n = 30), irregular morphological changes, i.e., an enlarged vessel diameter and vascular wall, were observed in all of the left posterior cerebral arteries (Lt PCAs) prone to rupture. Approximately 20% of rats had ruptured IAs within 6 weeks. In brain harboring unruptured IAs at the PCA, the mRNA levels of RAGE and MR were higher, and that of ATP1α3 was lower than those in the sham-operated rats (p < 0.05, each). Immunohistochemically, elevated expression of RAGE and MR, and decreased expression of ATP1α3 were observed in the brain parenchyma adjacent to the Lt PCA, resulting in increased Iba-1 and S100B expression that reflected the inflammatory changes. There was no difference between the unruptured and ruptured aneurysm rat groups. Treatment with the MR antagonist esaxerenone abrogated these changes, and led to cerebral and vascular normalization and prolonged subarachnoid hemorrhage-free survival (p < 0.05).

CONCLUSIONS

Regulation of the imbalance between the RAGE/MR pathway and ATP1α3 may help attenuate the damage in brain harboring IAs, and further studies are warranted to clarify the significance of the down-regulation of the MR/RAGE pathway and the up-regulation of ATP1α3 for attenuating the pathological changes in brain harboring IAs.

Inter-rater reliability of the simplified Modified Rankin Scale as an outcome measure for treated cerebral aneurysm patients

BACKGROUND

The modified Rankin scale (mRS) is commonly used as a clinical outcome measure in aneurysm trials, but inter-observer reliability in treated patients has not been tested.

METHODS

We reviewed the literature on inter-observer reliability studies of the mRS. Sixty patients with ruptured (n=47) or unruptured (n=13) aneurysms treated with endovascular methods (n=34) or surgical clipping (n=26) were independently evaluated by a neurosurgeon, a stroke neurologist, and a novice research assistant, and a simplified mRS score assigned. Results were analyzed using Gwet's AC_1/2 reliability coefficients (K_G).

RESULTS

No previous reports validating the reliability of the mRS in treated aneurysm patients were identified. Using the mRS 0-5, inter-rater agreement was almost perfect (K_G=0.89 [0.86-0.93]). Agreement between raters remained almost perfect regardless of the rater's expertise. Agreement was almost perfect (K_G=0.87 [0.77-0.96] when the mRS was dichotomized 0-2 vs 3-5, but fell to moderate when dichotomized 0-1 vs 2-5 (K_G=0.59 (0.42-0.75). Agreement using the 0-2 vs 3-5 dichotomized mRS remained almost perfect for coiled (K_G=0.90), clipped (K_G=0.82), ruptured (K_G=0.84), and unruptured (K_G=0.95) aneurysms. Dichotomization of results at 0-1 vs 2-5 would have resulted in an (undesirable) significant difference in good outcomes between raters (P=.003), but not at 0-2 vs 3-5 (P=.52).

CONCLUSION

The simplified mRS appears to be a reliable clinical outcome measure for treated cerebral aneurysm patients. When needed, dichotomization is more reliable at mRS 0-2 vs 3-5 than at 0-1 vs 2-5. The simplified mRS is a promising tool in the functional assessment of aneurysm patients recruited in pragmatic care trials.

Piggyback Stacking and Booster Clipping Technique: A Technical Note

In certain cases, the closing force of a single vascular clip is not sufficient for complete aneurysmal occlusion, and the use of multiple clips, or clip stacking, is required. Many stacking techniques have been described in the literature, such as in tandem stacking and overstacking. However, these may not be feasible during procedures with limited exposure or narrow corridors. Clip reinforcement with a second high-pressure booster clip, also known as the piggyback technique, is an alternative for these cases along with anatomically complex aneurysms or aneurysms demonstrating atypical morphological features. Although this technique has been cited as a potential resource for certain aneurysms, descriptions of its characteristics and advantages are scarce. The purpose of this technical note was to discuss our experience with the piggyback clipping technique and use of a booster clip for a partially embolized and recanalized saccular posterior communicating artery aneurysm in a 50 year-old patient.

Presurgical selection of the ideal aneurysm clip by the use of a three-dimensional planning system

Aneurysm occlusion rate after clipping is higher than after endovascular treatment. However, a certain percentage of incompletely clipped aneurysms remains. Presurgical selection of the proper aneurysm clips could potentially reduce the rate of incomplete clippings caused by inadequate clip geometry. The aim of the present study was to assess whether preoperative 3D image-based simulation allows for preoperative selection of a proper aneurysm clip for complete occlusion in individual cases. Patients harboring ruptured or unruptured cerebral aneurysms prior to surgical clipping were analyzed. CT angiography images were transferred to a 3D surgical-planning station (Dextroscope®) with imported models of 58 aneurysm clips. Intracranial vessels and aneurysms were segmented and the virtual aneurysm clips were placed at the aneurysm neck. Operating surgeons had information about the selected aneurysm clip, and patients underwent clipping. Intraoperative clip selection was documented and aneurysm occlusion rate was assessed by postoperative digital subtraction angiography. Nineteen patients were available for final analysis. In all patients, the most proximal clip at the aneurysm neck was the preselected clip. All aneurysms except one were fully occluded, as assessed by catheter angiography. One aneurysm had a small neck remnant that did not require secondary surgery and was occluded 15 months after surgery. 3D image-based preselection of a proper aneurysm clip can be translated to the operating room and avoids intraoperative clip selection. The associated occlusion rate of aneurysms is high.

Temporary vessel occlusion in cerebral aneurysm surgery guided by direct cortical motor evoked potentials

BACKGROUND

Temporary clipping is an important tool in the vascular neurosurgeon's armamentarium. We routinely utilize intraoperative neurophysiological monitoring (IONM) for complex brain aneurysm surgery cases, relying on direct cortical motor evoked potential (DCMEP) alerts to guide the duration of temporary clipping. Previous studies have argued for relatively short and intermittent temporary clipping strategies. In this study, we sought to assess the maximal permissive temporary clipping time during complex aneurysm surgery. To do this, we assessed patient outcome in relation to temporary clip duration guided by DCMEP.

METHODS

We queried our prospectively collected neuromonitoring database for anterior circulation aneurysm cases where temporary clipping was utilized by a single cerebrovascular surgeon between 2018 and 2021. Operative and IONM reports were reviewed. Patients in whom the duration of temporary clipping could not be determined were excluded. The operative strategy permissively allowed continuous temporary clipping as long as no neuromonitoring alerts were encountered. Maximal permissive parent artery occlusion time (Clip_max) was recorded as the longest duration of tolerated temporary vessel clipping without decrement in DCMEP.

RESULTS

A total of 41 complex anterior circulation aneurysm clipping cases met criteria for this study. The mean Clip_max for all cases was just over 19 min and did not differ between ruptured and unruptured aneurysms. Initial alert times were not found to be predictive of final permissive temporary clip duration after re-perfusion. In 100% (41/41) of cases, the aneurysm was completely clip occluded without residual on catheter angiogram. Stable or improved modified Rankin Score was achieved in 98% (40/41) of cases at 3-month follow-up.

CONCLUSIONS

This study demonstrates that using DCMEP can facilitate relatively long but safe temporary clipping durations in complex anterior circulation aneurysm surgery. In the endovascular era with only a limited subset of technically challenging aneurysms needing open surgical treatment, extended permissive temporary clipping guided by DCMEPs can significantly enhance a surgeon's ability to achieve excellent technical and clinical outcomes.

Long-Term Characteristics of De Novo Bleb Formation at the Aneurysm Neck After Coil Embolization in Unruptured Cerebral Aneurysms

OBJECTIVE

De novo bleb formation at the aneurysm neck after coil embolization of unruptured intracranial aneurysms is a rarely observed type of recurrence. The aim of this study was to elucidate the clinical characteristics of recurrent aneurysms in the long-term period.

METHODS

Between January 2002 and December 2015, 290 unruptured intracranial aneurysms were treated with coil embolization at our institution. Patients who underwent retreatment due to aneurysm recurrence were divided into 2 patterns of recanalization: de novo bleb formation at the neck of a coiled sac (type DNV) and an enlarged residual cavity without de novo bleb formation (type non-DNV).

RESULTS

Twenty-seven patients with aneurysms (9.3%) underwent retreatment (type DNV, 7; type non-DNV, 20). The initial aneurysm size of type DNV aneurysms was significantly smaller than that of type non-DNV (6.1 ± 2.2 mm vs. 10.1 ± 3.6 mm; P < 0.01), and time to retreatment in type DNV was significantly longer than that in type non-DNV (9.4 ± 5.3 years vs. 2.0 ± 2.0 years; P < 0.01). Two type DNV basilar artery (BA) aneurysms ruptured after a few years; however, the other type DNV aneurysms, including 4 anterior circulation aneurysms (including the internal carotid artery), were observed to grow gradually without rupture for >10 years until retreatment.

CONCLUSIONS

De novo bleb formation at the neck of a coiled sac emerges with insidious growth during long-term follow-up. Constant caution should be exercised, even in cases of small- and medium-sized anterior circulation aneurysms. A risk of rupture risk may be anticipated, especially in BA lesions.

Aberrant right subclavian artery with right type 1 proatlantal artery and segmental dysplasia of the right internal carotid artery: a case report

PURPOSE

We present a case of an aberrant right subclavian artery (ARSA) with extremely rare vascular anomalies.

CASE REPORT

A 69-year-old woman was suspected to have right internal carotid artery (ICA) stenosis. Computed tomography angiography demonstrated an ARSA and hypoplasia of the right ICA. The proximal segment of the right vertebral artery (VA) was aplasia, and a right type 1 proatlantal artery (PA) arose from the right common carotid artery. Cerebral angiography demonstrated segmental dysplasia of the right ICA. The ascending intrapetrous segment and the ascending foramen lacerum-horizontal intracavernous segment of the right ICA demonstrated hypoplasia. The collateral pathways promoted reconstitution of each of the distal segments. Left internal carotid angiography demonstrated anterior communicating artery aneurysm and sufficient cross flow to the contralateral middle cerebral artery via the AcomA.

DISCUSSION

A type 1 PA with an ARSA may result in the regression of the right dorsal aorta with persistence of the first cervical intersegmental artery. Although there are few findings of a relationship between an ARSA and intracranial artery anomalies, a developmental error of the right dorsal aorta may cause such complex vascular anomalies.

CONCLUSION

Knowledge of anatomical variations in patients with ARSA is useful when performing angiography or endovascular therapy, as well as during clinical follow-up.

Prevalence of cerebral aneurysms in autopsy studies: a review of the literature

Cerebral aneurysms (CAs) are one of the most important causes of stroke, but details of their prevalence remain under-researched. Autopsy data for CAs were reviewed using standard search engines. Based on previously published autopsy and clinical studies, the prevalence of CAs with respect to age, gender, and aneurysm site, size, and multiplicity was investigated, and the natural course of CA prevalence was estimated. In autopsy studies, the prevalence of CAs across all age groups was 0.3-4.0% for unruptured cerebral aneurysms (UCAs) and 1.3-7.6% for CAs including UCAs and ruptured cerebral aneurysms (RCAs). Patients with UCAs were generally older than those with RCAs. Middle cerebral artery aneurysms were more predominant in autopsy studies than in clinical studies. UCAs tended to be smaller than RCAs, and minute UCAs (< 2 mm), diagnosed microscopically at autopsy and thought to be in the very early stages of formation, were present in 10-20% of the general population. Taking into consideration the clinical data for UCAs and RCAs, 10% of minute UCAs enlarge to major UCAs (≥ 2 mm) detectable by conventional imaging techniques, and 10% of major UCAs eventually rupture within 10 years. The high prevalence of UCAs and RCAs in the elderly and women can be attributed to the more frequent occurrence of minute UCAs in these populations. Minute UCAs occur at a high rate, but only a few enlarge to become major UCAs and rupture. Further advances in diagnostic technology are essential for revealing the true natural course of CA prevalence.

Suction thrombectomy using a microcatheter as a salvage method for acute distal occlusion during cerebral aneurysm embolization: A case report

The aneurysm coiling process presents a risk of thromboembolic complications, mostly in patients with ruptured aneurysms, given the fact that they cannot receive antiplatelet therapy. Management strategies include medical anticoagulation or antiplatelet therapy, intra-arterial thrombolysis, and mechanical thrombectomy using direct aspiration first-pass technique or stent retrievers. We report our own experience of using an Excelsior SL-10 Microcatheter (Stryker, Fremont, California, USA) with an internal diameter of 0.0165”, originally designed for coil delivery, for contact aspiration of a thrombotic occlusion of a distal anterior cerebral artery during coiling of a broad-based trilobar anterior communicating artery aneurysm. The clot was removed under continuous manual aspiration, and complete recanalization has been accomplished. Mechanical thrombectomy through microcatheter aspiration may be a safe and feasible treatment option for acute distal artery occlusions, especially in the case of tortuous distal vessels during embolization of cerebral aneurysms.

Management of Complex Cerebral Aneurysms

BACKGROUND

Complex intracranial aneurysms (CIAs) are challenging pathologies to treat. Characteristics making an aneurysm complex include dimension, history of previous treatment, location, absence of collateral circulation, intraluminal thrombosis, and calcification of the wall. The goal of the therapeutic process is to exclude the malformation from the cerebral circulation and both endovascular and surgical treatments are valid procedures.

METHODS

Between 1990 and 2020, 170 CIAs were treated at our institution (33 ruptured, 137 unruptured). They were 3 prepetrous segment of the internal carotid artery (ICA), 14 purely intracavernous sinus, 27 intracavernous with subarachnoid extension, 60 paraclinoid, 4 ICA bifurcation, 15 anterior communicating artery, 24 middle cerebral artery, and 23 in the posterior circulation. All the patients underwent neuroradiologic examinations and images were evaluated by the neurosurgical and interventional radiologist team. Endovascular treatment was considered as the treatment of choice. Alternative treatment was surgical clipping; revascularization procedures were performed when neither endovascular treatment nor direct clipping were possible.

RESULTS

Of 170 patients, 45 underwent endovascular treatment, 77 surgical clipping, and 55 revascularization procedures. In the unruptured group, 12 patients died, 22 reported major complications, 3 had minor complications, and 101 had an uneventful postoperative course. In the ruptured group, 9 patients died, 10 had minor complications, 1 minor complication, and 13 had a complete recovery.

CONCLUSIONS

Endovascular treatment should represent the treatment of choice for CIAs. Alternative treatments include direct surgical clipping and revascularization. Overall, the correct identification of the therapeutic process guarantees a good clinical outcome.

Initial Experience with Left Transradial Neurointerventions for Cerebral Aneurysms Using the 6-French Simmons Guiding Sheath

OBJECTIVE

The use of a transradial approach utilizing a Simmons-shaped catheter for neurointervention has been steadily increasing. Although the right radial artery is commonly used, in interventional cardiology, the left transradial approach offers clear clinical benefits for right-handed patients. To the best of our knowledge, no previous studies have examined intracranial aneurysm embolization with the routine use of the left transradial approach. The aim of this study was to evaluate the technical feasibility of left transradial intracranial aneurysm embolization.

METHODS

We conducted a retrospective review of a prospective database of consecutive patients who had undergone left transradial intracranial aneurysm coiling using a 6-French Simmons guiding sheath between January and August 2021. The following outcome variables were then analyzed: whether the catheterization was successful, the angiographical results, and the presence of any procedure-related complications.

RESULTS

In total, 25 patients underwent left transradial coiling for 15 anterior and 10 posterior circulation aneurysms. The Simmons guiding sheath could be successfully shaped and cannulated into the targeted vessel in all patients. All aneurysms were completely embolized without any complications. Immediate postoperative angiograms showed Raymond 1 in 10 aneurysms (40.0%), Raymond 2 in 12 (48.0%), and Raymond 3a in 3 (12.0%). None of the patients required crossover to the right radial or femoral arteries, and no radial artery spasms or occlusions were observed.

CONCLUSION

The results of this study suggest that the left transradial approach for intracranial aneurysm coiling is not only safe, effective, and technically feasible, but also provides improved comfort to right-handed patients.

Keyhole Approach in Cerebral Aneurysm Surgeries

Pterional approach via standard fronto-temporal craniotomy and interhemispheric approach via bifrontal craniotomy are the gold standards for clipping of cerebral aneurysms in the anterior circulation. Endovascular treatment is now widely used, but subsets of aneurysms are still indicated for surgical clipping. Modern technological advances allow less invasive clipping techniques such as the keyhole approach. This chapter discusses the surgical indications, preoperative simulation, surgical techniques, and pros and cons of keyhole (supraorbital) clipping. Selection of standard craniotomy or keyhole craniotomy should be uncontroversial, but keyhole clipping requires definite surgical indications based on the characteristics of the target aneurysm for safe clipping.

Repeated Aneurysm Intervention

Over the past 25 years the endovascular treatment of cerebral aneurysms has gained preference in some countries over the traditional surgical procedures. The review part of the article clearly demonstrates that the clinical results of both modalities are similar and the difference is seen only in technical effectivity. Surgical techniques fail far less frequently than the endovascular ones. Incompletely occluded or growing aneurysms after the endovascular approach expose the patient to the risk of rebleeding with all possible consequences. Markedly repeated procedures are much more common for endovascularly treated aneurysms, again with all the risks.In the authors institution over the past 20 years, a total of 2032 aneurysms were treated. In 1263 endovascularly managed aneurysms the regrowth or inclomplete initial occlusion necessitated 159 repeated propcedures (12.6%). In surgical group the total of 27 aneurysms needed retreatment (3.5%). The difference is statistically significant. In nine patients in endovascular group the rebleeding was the reason for repeated procedures. No rebleeding was seen in the surgical group.This fact, also shown in the review part of the article, is important in patients counseling. Given the similar clinical results of both modalities the patient should be advised on the necessity of repeated follow-ups and of possible technical failure and eventual repeated procedure which is more likely if endovascular procedure is chosen.

Posterior Circulation Aneurysms

Posterior circulation aneurysms have a higher tendency to rupture and become symptomatic in comparison to anterior circulation aneurysms. Current treatment modalities for aneurysms in these locations vary widely including microsurgical clipping, trapping with bypass, wrapping, and various endovascular methods such as coiling, balloon or stent-assisted coiling, flow diversion, and vessel sacrifice, among others.Overall, surgical versus endovascular treatment of posterior circulation aneurysms continue to be a controversial topic in cerebrovascular neurosurgery. At our center, multi-disciplinary assessments including surgeons capable of both endovascular and microsurgical treatments of these aneurysms are employed to guide the treatment strategies. As advancements in both fields are made, this will continue to be a topic for debate. Anatomy and individual patient's characteristics will dictate the correct approach and therefore proficiency in the microsurgical techniques required to treat these aneurysms will continue to be both relevant and important.

Multiplanar CT evaluation of aneurysm rupture signs in subarachnoid hemorrhage

PURPOSE

In subarachnoid hemorrhage, noncontrast CT features are used to guide the localization of ruptured aneurysms on CT angiography and DSA. Multiplanar CT may improve the localization of aneurysm rupture sites over axial plane CT alone.

METHODS

Multiplanar CT in three orthogonal planes was used to evaluate 94 cases of SAH. Two investigators independently evaluated each imaging plane for focal thick SAH with mass effect, intracerebral hemorrhage, focal edema, filling defect, subdural hemorrhage, and dominant intraventricular hemorrhage. Also, rupture site was qualitatively identified by combining these variables in each plane and combination of three planes. DSA served as the gold standard to locate the rupture sites.

RESULTS

Interobserver agreement was k 0.60 to 0.79 for axial, k 0.43 to 0.86 for coronal and k 0.43 to 0.74 for sagittal planes. Good to substantial agreement was observed for the localization of rupture site in three planes (focal SAH with mass effect - k 0.78 to 0.85; filling defect - k 0.95 to 1.0; intracerebral hemorrhage - k 1.0; focal edema k 1.0; subdural hemorrhage - k 0.61 to 0.83). Dominant intraventricular hemorrhage revealed significant association with DSA to locate ruptured aneurysms (Fisher's exact test - Pr <  = P (< 0.001)). With non-missing data, frequency of correct ratings to locate rupture site was 66/67 (99%) in axial plane, 59/66 (89%) in coronal plane, 64/67 (96%) in sagittal plane and 77/77 (100%) in combined 3 planes.

CONCLUSIONS

Multiplanar CT head is more successful than axial plane CT alone for the localization of aneurysm rupture sites in SAH.

Cortical Spreading Depolarizations in Aneurysmal Subarachnoid Hemorrhage: An Overview of Current Knowledge and Future Perspectives

Despite significant advances in the management of aneurysmal subarachnoid hemorrhage (SAH), morbidity and mortality remain devastating particularly for high-grade SAH. Poor functional outcome usually results from delayed cerebral ischemia (DCI). The pathogenesis of DCI during aneurysmal SAH has historically been attributed to cerebral vasospasm, but spreading depolarizations (SDs) are now considered to play a central role in DCI. During SAH, SDs may produce an inverse hemodynamic response leading to spreading ischemia. Several animal models have contributed to a better understanding of the pathogenesis of SDs during aneurysmal SAH and provided new therapeutic approaches including N-methyl-D-aspartate receptor antagonists and phosphodiesterase inhibitors. Herein we review the current knowledge in the field of SDs' pathogenesis and we detail the key experimental and clinical studies that have opened interesting new therapeutic approaches to prevent DCI in aneurysmal SAH.

Surgery and intraoperative neurophysiologic monitoring for aneurysm clipping

This chapter describes the feasibility, utilization, and value of intraoperative neurophysiologic monitoring (IONM) in cerebrovascular cases. Practical advice on the integration of these adjunct methods into the modern neurosurgical operating room is based on our own neurophysiologic and neurosurgical experience. Most IONM is done for anterior circulation aneurysms. Somatosensory and motor evoked potentials are the modalities of choice covering vascular territories of the internal, anterior, and middle cerebral arteries. While monitoring both hemispheres with the unoperated side as control, monitoring focus is laid upon those territories at risk and bearing the aneurysm. The specificity of IONM is close to 1, and sensitivity ranges from 0.2 to 1, depending on the categorization of transient changes. The overall likelihood of worsened neurologic outcome after any intraoperative signal deterioration (transient or permanent) is 0.4.

Nicotine Replacement Therapy for Smokers with Acute Aneurysmal Subarachnoid Hemorrhage: An International Survey

INTRODUCTION

Smoking prevalence is twice as high among patients admitted to hospital because of the acute condition of aneurysmal subarachnoid hemorrhage (aSAH) as in the general population. Smoking cessation may improve the prognosis of aSAH, but nicotine replacement therapy (NRT) administered at the time of aSAH remains controversial because of potential adverse effects such as cerebral vasospasm. We investigated the international practice of NRT use for aSAH among neurosurgeons.

METHODS

The online SurveyMonkey software was used to administer a 15-question, 5-min online questionnaire. An invitation link was sent to those 1425 of 1988 members of the European Association of Neurosurgical Societies (EANS) who agreed to participate in surveys to assess treatment strategies for withdrawal of tobacco smoking during aSAH. Factors contributing to physicians' posture towards NRT were assessed.

RESULTS

A total of 158 physicians from 50 nations participated in the survey (response rate 11.1%); 68.4% (108) were affiliated with university hospitals and 67.7% (107) practiced at high-volume neurovascular centers with at least 30 treated aSAH cases per year. Overall, 55.7% (88) of physicians offered NRT to smokers with aSAH, 22.1% (35) offered non-NRT support including non-nicotine medication and counselling, while the remaining 22.1% (35) did not actively support smoking cessation. When smoking was not possible, 42.4% (67) of physicians expected better clinical outcomes when prescribing NRT instead of nicotine deprivation, 36.1% (57) were uncertain, 13.9% (22) assumed unaffected outcomes, and 7.6% (12) assumed worse outcomes. Only 22.8% (36) physicians had access to a local smoking cessation team in their practice, of whom half expected better outcomes with NRT as compared to deprivation.

CONCLUSIONS

A small majority of the surveyed physicians of the EANS offered NRT to support smoking cessation in hospitalized patients with aSAH. However, less than half believed that NRT could positively impact clinical outcome as compared to deprivation. This survey demonstrated the lack of consensus regarding use of NRT for hospitalized smokers with aSAH.

Risk factors and outcome analysis of patients with intraoperative rupture (IOR) of ruptured cerebral aneurysm during microsurgical clipping

PURPOSE

To analyse baseline characteristics of patients with intraoperative rupture (IOR) or non-IOR who underwent microsurgical clipping for ruptured intracranial aneurysms. Additionally, to asses functional outcome in terms of Glasgow Outcome Scale (GOS) at 6 and 12 months.

METHODS

A retrospective analysis of 471 patients who underwent microsurgical clipping for ruptured intracranial aneurysms from 2007 to 2018 in Nepal Mediciti Hospital, Nepal. Patients who underwent surgery for unruptured aneurysm were excluded from the study. The association of the base line characteristic in IOR and non-IOR were analysed. Variables analysed were the Hunt and Hess Scale (HHS) dichotomized as (1-3) and (4-5), Modified Fisher Scale dichotomized as (0-2) and (3-4), type of rupture, use of brain retractor, timing of IOR during surgery, aneurysmal factors (size of the neck, location, lobulation) and time of surgery. Outcome, GOS dichotomized into favourable (4-5) and unfavourable (1-3), assessed at 6 months and 12 months.

RESULTS

Out of 471 patients treated for ruptured intracranial aneurysm, IOR occurred in 57 (12.10%) with mean age 49.47 (SD ±12.9), occurred more in smoker than non-smoker (45.6% vs. 18.6%; p=.000) and regular alcohol consumers (36.8% vs. 17.9%; p=.004). Favourable outcome with GOS (4-5) at 6 months was observed among patients with lower HHS (1-3), p=.025 and lower MFS (0-2), p=.04. However, outcome at 12 months was better associated with MFS (p=.013) and aneurysm size (p=.038), with more favourable outcome associated with aneurysm less than 10 mm.

CONCLUSIONS

Alcohol consumption and smoking are associated risk factors that may contribute to IOR. HHS and MFS are strong predictors of outcome for IOR patients at 6 months. However, at 12 months, MFS is more predictive of outcome. Aneurysms greater than 10 mm had a strong association with outcome at 12 months than 6 months.

Cerebral aneurysms in pediatrics: a case report and review of the literature

BACKGROUND

Cerebral aneurysms in pediatrics represent < 4% of the total of this condition, and their rupture represents 10-23% mortality. Aneurysms have been associated with infections, head injuries, sickle cell anemia, cardiovascular diseases, autoimmune diseases, immunodeficiencies, and connective tissue diseases. Their clinical presentation includes severe headache, seizures, motor-sensory deficits, and death due to subarachnoid and intraparenchymal hemorrhage.

CASE REPORT

We describe the case of a 12-year-old female patient who presented with a sudden intense headache; after 72 hours, generalized tonic-clonic seizures were observed. At the hospital, she was stabilized with antiepileptic drugs and analgesics. A simple head computed tomography scan showed intraparenchymal hemorrhage in the right frontal lobe and subarachnoid hemorrhage. The study was complemented with a cerebral angiotomography, which revealed an aneurysm of the anterior communicating artery. The pediatric neurosurgeon evaluated the case, and management in the pediatric intensive care unit was decided. Two weeks after the stroke, the aneurysm was clipped and excluded. The patient developed adequate clinical evolution and resolution of initial symptoms, resuming her daily activities.

CONCLUSIONS

Pediatric cerebral aneurysms differ from their adult counterparts, mainly in their etiology and evolution. In addition, pediatric patients have a longer life expectancy. Aneurysm clipping and neurological endovascular therapy have shown similar results.

Extremely tortuous superior cerebellar artery mimicking an aneurysm

Background:

An extremely tortuous superior cerebellar artery is a rare anomaly. We report a case of an extremely tortuous superior cerebellar artery mimicking an aneurysm.

Case Description:

A 77-year-old woman was initially diagnosed with unruptured cerebral aneurysm at the right basilar artery-superior cerebellar artery junction by magnetic resonance angiography. Catheter angiogram revealed that there was no apparent aneurysm at the basilar artery-superior cerebellar artery junction and the lesion was actually an extremely tortuous superior cerebellar artery.

Conclusion:

Although an extremely tortuous superior cerebellar artery is rare, it should be considered when examining other vascular lesions.

Does establishing a neurovascular unit improve the outcome after surgical clipping for aneurysmal subarachnoid hemorrhage? Results from a 5-year observational study in Kuwait

Background:

Failure to prevent rebleeding after cerebral subarachnoid hemorrhage (SAH) is the most frequent reason for high morbidity and mortality of aneurysmal SAH. Our study aims to identify the outcome after surgical clipping of aneurysmal SAH before and after the establishment of the neurovascular unit. The clarifications of the positive turnover in the outcome will be discussed.

Methods:

A retrospective cohort analysis was carried out on our experience with a controlled group of patients who underwent clipping for ruptured cerebral aneurysms (n = 61) from January 2015 to December 2019. A modified Rankin scale (mRS) was used to determine the outcome after 6 months of follow-up.

Results:

The median mRS score (i.e., outcome) on admission was 4, whereas it was with a median score of 2 six months after clipping (P ≤ 0.001). Overall, the cases with a good outcome were 63.9% of the sample, while the poor outcome conditions were 36.1%. The most cases with an improved outcome were after introducing the neurovascular unit, representing a transition of aneurysmal clipping practice in our center. The good outcome was changed from 42% to 76.7%, and the poor outcome was changed from 58% to 23.3% (P = 0.019). The crude mortality rate was similar to the rate worldwide (18%), with a noticeable decrease after organizing a neurovascular subspecialty.

Conclusion:

The outcome after clipping of ruptured SAH can be largely affected by the surgeon’s experience and postoperative intensive care. Organizing a neurovascular team is one of the major factors to achieve good outcomes.

Intraoperative motor-evoked potential monitoring during coil embolization for anterior choroidal artery aneurysms

PURPOSE

Intraoperative motor-evoked potential (MEP) monitoring is widely used in the neck clipping of cerebral aneurysms. Little is known regarding the usefulness of intraoperative MEP monitoring in endovascular aneurysm surgery. The purpose of this study was to validate the feasibility of intraoperative MEP monitoring during the coil embolization of anterior choroidal artery (AChA) aneurysms.

METHODS

Clinical and angiographic data of consecutive patients who underwent coil embolization for unruptured AChA aneurysms with or without intraoperative MEP monitoring between January 2014 and December 2018 at our institute were abstracted and analyzed retrospectively.

RESULTS

Twenty-three unruptured AChA aneurysms were treated. Eleven patients received MEP monitoring, and three of them experienced intraoperative reduction or disappearance of the MEP wave. Even during MEP changes, AChA filling showed no change in any of the three cases. Although one case with MEP monitoring encountered the disappearance of AChA filling, there was no change in MEP. This might be due to retrograde filling of the AChA from the anastomosis with the lateral posterior choroidal artery. AChA blood flow detected by angiography did not always reflect MEP status. When comparing the presence or absence of MEP monitoring, the volume embolization ratio of coiled aneurysms was significantly better in the MEP group.

CONCLUSION

Intraoperative MEP monitoring during endovascular coiling for AChA aneurysms may be feasible. AChA blood flow detected by angiography does not always reflect MEP status.

Clipping of Multiple Cerebral Aneurysms Through Cranioorbital Zygomatic Approach: 2-Dimensional Operative Video

Ruptured cerebral aneurysm is a grave disease, with a high morbidity and mortality, mandating securing the aneurysm to eliminate fatal rebleeding.1 Multiple aneurysms are frequent and may occur in approximately 20% of the cases with female prominence.2 The risk of subarachnoid hemorrhage in unruptured aneurysms is higher in patients who had prior ruptured aneurysms.3 Hence, there is an indication of treating all concomitant aneurysms when one is ruptured. We present the case of clipping of 3 aneurysms via a cranioobritozygomatic (COZ) approach including a middle cerebral artery, anterior choroidal artery, and superior cerebellar artery in a patient presenting with subarachnoid hemorrhage and multiple aneurysms with suboptimal morphology for endovascular coiling. We highlight the advantages of the COZ in the clipping of complex posterior circulation aneurysms and the advantage of mobilization of neural structures to gain wider exposure.4-6 The temporal fossa space provided by zygomatic osteotomy allows the outward mobilization of the temporal lobe after freeing it by splitting the Sylvian fissure. The falciform ligament is opened overlying the optic nerve, allowing for safe dissection within the opticocarotid window. The oculomotor nerve is detethered from the dura surrounding its entry into the cavernous sinus. These maneuvers allow for mobilization of the critical neurovascular structures, which widens the operative corridor without undue traction or retraction. The COZ with clinoidectomy shortens and widens the operative field, allows for enhanced maneuverability, improved visualization, and exposure of the clinoidal carotid, and facilitates the release and mobilization of the optic and third nerve. The patient consented to surgery.  Image at 1:40 reprinted with permission from Al-Mefty O, Operative Atlas of Meningiomas. Vol 1, © LWW, 1998.